Cable press with stationary press-head



May 27, .1958 E. MULLER ET AL 2,336,295

CABLE PRESS WITH STATIONARY PRESS-HEAD 'Filed Nov. 18, 1952 [VVf/VTOZSASE/V57 M04452 Aueusr GEOHMANN 7 7740170 1, n ul-ldmo plg THE/z Ame/vex;

.United States Patent- CABLE PRESS WITH STATIONARY PRESS-HEAD ErnstMiiller and August Grohmann, Duisburg, Germany, assignors to HydraulikG. in. b. H., Duisburg, Germany, a German company Application November18, 1952, Serial No. 321,244

1 Claim. (Cl. 207-22) The invention relates to a sheathing press inwhich a sheathing is provided for cables and the like, and which isparticularly intended to press light metals and light metal alloys. Sucha press is operated with a stationary press-head and two dies moved inopposite directions, which force equal quantities of the pressedmaterial into the press-head.

In such known presses, one of the difliculties is the problem of movingthe rams in opposite directions in such manner that they force out equalvolumes at equal periods.

The known devices, by which this reverse motion is ensured, are heavy,bulky and expensive, and necessitate complicated control devices.

The invention is based on the discovery that in practice any resistancedifferences that do occur between the two pressed materials do notexceed a certain magnitude, so that balancing may be effected by meansof devices which transmit only limited pressures, which in any case maybe readily controlled constructionally and operationally.

According to the invention the oppositely directed rams are connected bymeans of a hydraulic power line which efiects the balancing When thepressure resistances are diflerent. This hydraulic power line entails atleast one of the rams being provided with a larger diameter than theother and with a secondary cylinder, said cylinder being connected to asecondary cylinder of the opposite ram by means of a fluid-pipe. Onesecondary piston displaces as much fluid as is released by the othersecondary piston, with exactly oppositely directed rams. If, due to aresistance difference, one ram remains stationary it will be suppliedwith energy by the secondary cylinder through the power linehereinbefore described, so that pressure is applied to effect thereverse motion.

The power line includes one secondary piston for each ram, and a thirdsecondary piston on which the smaller ram acts.

When the diameter of one ram exceeds that of the other, a rammingpressure is constantly transmitted from one ram to the other through thehydraulic power line. Instead of having the diameter of one ram larger,it is also possible to provide additional cylinders, which serve thesame purpose and render it possible to transmit to one side more energythan to the other and to transmit this excess energy through thehydraulic power line to the opposite side in spite of the diameters ofthe rams being the same.

The addition of the secondary cylinders, and if necessary or desired, ofthe additional cylinders, need not imply a substantial complication ofthe press, as most of these cylinders may be designed as return strokecylinders which are required in any case. The control is providedaccordingly.

The figure shows a diagram of the press with two pairs of hydraulicpower lines between the rams. The two receivers 2 and 3 into which thepressed material indicated at 4 is forced by the rams 5 and 6 areprovided 2,836,295 Patented May 1958 ICC on the stationary press-head 1.The rams are mounted on the cross-heads 7 and 8, which are operated bythe rams 9 and 10a in the cylinders 11 and 120. Ram 10a and cylinder 12aare larger in diameter than ram 9 and cylinder 11.

To the cross-head 7 are connected the secondary pistons 39, theco-operating cylinders 31 of which are provided on the support 15 forthe receivers, that is to say, they are stationary. When the ram 5 movesdownwardly, the pistons 30 are also moved downwardly. The fluiddisplaced thereby in the cylinders 31 is fed through the pipes 16 to thehydraulic main.

As the force on the ram 6 is greater, the ram is inclined to lead theram 5, but, additional ramming pres sure is fed thereto through thepiston 20 and the pipe 22 as well as the cylinders 23 and the pistons24, so that an exactly equal oppositely directed motion is obtainedautomatically.

The control devices 25 render it possible to release the hydrauliccoupling between the cylinders 21 and 23 in that the line 22 can beopened against atmosphere so that the occurrence of pressure therein isavoided. In this manner it is possible to move the cross-heads 7 and 8independently of each other towards the pressure head. By means of thecontrol means 25 it is also possible to introduce pressure fluid fromthe outside into the cylinder 21 in order to be able to move thecross-head 8 independently. The independent retraction of the crosshead7 by the piston 30 can be efiected by introducing water under pressureat 16 when the control means 25 allows the liquid to flow ofi from thecylinders 23. When, however, the control means 25 are so adjusted thatthe connecting lines 22are closed upon themselves, then the hydrauliclinkage between the cylinders 23 and 21 is also effective during theretraction movement of the cross-heads 7 and 8 inasmuch as it is onlynecessary to introduce water under pressure through the line into thecylinders 31.

The control members 25 are used for effecting operation of the hydraulicpower line by controlling the direction of the flow of fluid through thelines.

The secondary pistons 20 may be used for the return movement of thepiston 10a. Special additional pistons 30 with corresponding cylinders31 are provided for the piston 9.

These secondary pistons may be used to pass a greater flow of energy toone side of the press, even when the diameters of the rams 9 and 10a areequal. In this case, the cylinders 31 are connected to the hydraulicmain of the pressure cylinders also during the pressure stroke, so thatthe piston 30 counteracts the piston 9, the result being the same as ifthe piston 9 had a smaller diameter than the piston 10a. The fact thatthe piston 30 is used for this purpose does not exclude the possibilityof its being also used as a return-stroke piston.

We claim:

A press for the sheathing of cables and the like, particularly forpressing light metal and metal alloys, comprising a frame, a stationarypress-head to hold the metal to be pressed, oppositely acting ramsmounted on movable cross-heads to press the metal in the press-head fromtwo sides, main cylinders mounted on the frame, one of said cylindershaving a diameter larger than the other, pressure fluid actuated pistonsof different diameter in the main cyinders secured to the ramcross-heads to move the rams in a metal-pressing direction, secondarycylinders mounted on opposite sides of the press-head, pressure fluidactuated pistons in the secondary cylinders secured to opposite sides ofeach ram cross-head for retracting said rams and said cross-heads,further secondary cylinders mounted on the frame, pressure fluidactuated pistons therein secured to one of said ram crossg-retractingthe other ram cmgs head whi ch is actuated 5 by said 1 nain pistotxfgreater diameter, thus balancing heads; which .is :actuated by'sziidmain piston of smallety pressure fluid-1t0 or between the secondarycylinder: to 7 diameter, "to move in metal-pressing direction,conneccause the pistons to alternately balance or move the ram tiotimeans' between said last secondary cylinders and p y- H v V saidsecondarycyhnders'mounted on the press-head for 7 References Cited inthgfile of this patent UNITED STATES PATENTS the press head on theramicross-head pf the smaller Re. 13,562 Summey;v 5 May 13, 1913 mainpiston', and va1ve-means for'selectively valving the 1,109,555 SummeySept. 1, 1914 V

